Impact of dietary fat on Th1/Th2 cytokine gene expression in the pancreas and gut of diabetes-prone BB rats.
The effect of dietary n-3 or n-6 polyunsaturated fatty acids on the development of autoimmune insulitis was analysed in diabetes-prone BB rats. Litter-matched groups of rats received a standard open formula NIH-07 (National Institutes of Health, NIH) diet enriched with 10% fish oil, 10% flaxseed oil or with 10% palm oil plus 2% cholesterol during the period of insulitis onset (50-70 days of age). Analysis of cytokine gene expression in pancreatic RNA revealed an increase of IFN-gamma and a decrease of IL-10 mRNA with onset of insulitis. When compared to unsupplemented NIH, none of the three fat-enriched diets depressed the rise of IFN-gamma gene expression or the influx of leukocytes into islets. However, all of the fat-enriched diets led to significantly higher IL-10 mRNA levels. Although a specific anti-inflammatory effect of fish oil was not seen in the pancreas, a clear shift of the Th1/Th2 cytokine mRNA ratio towards Th2 was seen in the gut-associated immune system. We conclude that diets high in fat support IL-10 without suppressing IFN-gamma gene expression in islet inflammation. A special anti-inflammatory effect of fish oil was not seen in pancreatic lesions of BB rats, although there was strong modulation of the IFN-gamma/IL-10 mRNA ratio in the gut associated immune system.
Kleemann
R
R
Diabetes Research Institute, University of Düsseldorf, Germany.
Scott
F W
FW
Wörz-Pagenstert
U
U
Nimal Ratnayake
W M
WM
Kolb
H
H
D000818:Animals; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics*; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics / Q000276:immunology*; D004041:Dietary Fats / Q000008:administration & dosage*; D004198:Disease Susceptibility; D005227:Fatty Acids / Q000008:administration & dosage / Q000378:metabolism; D005395:Fish Oils / Q000008:administration & dosage; D005786:Gene Expression Regulation / Q000187:drug effects*; D007421:Intestine, Small / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D008043:Linseed Oil / Q000008:administration & dosage; D009928:Organ Specificity / Q000187:drug effects; D010179:Pancreas / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D010581:Peyer's Patches / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D051381:Rats; D011913:Rats, Inbred BB; D018417:Th1 Cells / Q000187:drug effects / Q000378:metabolism*; D018418:Th2 Cells / Q000187:drug effects / Q000378:metabolism*
D016207:Cytokines; D004041:Dietary Fats; D005227:Fatty Acids; D005395:Fish Oils; D008043:Linseed Oil